A compound of the formula I ##STR00001## in which the moieties R.sup.1-R.sup.13 are independently selected from the following moieties: R.sup.1, R.sup.5, R.sup.6, R.sup.8, R.sup.11--H, methyl, ethyl, propyl, isopropyl; R.sup.3--H, methyl, ethyl, propyl, isopropyl, vinyl; R.sup.4--H, methyl, ethyl; R.sup.2, R.sup.7, R.sup.9--H, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl; R.sup.10--H, methyl, ethyl, propyl, isopropyl, t-butyl; R.sup.12, R.sup.13--H, C.sub.1-6 linear or branched alkyl; or R.sup.4 and R.sup.11 together with the carbon atoms to which they are attached form a 5- or a 6-membered cycloalkyl ring; or R.sup.6 and R.sup.7 together with the carbon atoms to which they are attached form a cycloalkyl ring having 3, 4, 5 or 6 members. The compounds have strong odours and are useful in fragrances and fragrance applications.

Claim:

The invention claimed is:

1. A compound of the formula I ##STR00004## in which the moieties R.sup.1-R.sup.13 are independently selected from the following moieties: R.sup.1, R.sup.5, R.sup.6,R.sup.8, R.sup.11--H, methyl, ethyl, propyl, isopropyl; R.sup.3--H, methyl, ethyl, propyl, isopropyl, vinyl; R.sup.4--H, methyl, ethyl; R.sup.2, R.sup.7, R.sup.9--H, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl; R.sup.10--H, methyl,ethyl, propyl, isopropyl, t-butyl; R.sup.12, R.sup.13--H, C.sub.1-6 linear or branched alkyl; or R.sup.4 and R.sup.11 together with the carbon atoms to which they are attached form a 5- or a 6-membered cycloalkyl ring; or R.sup.6 and R.sup.7 togetherwith the carbon atoms to which they are attached form a cycloalkyl ring having 3, 4, 5 or 6 members.

This invention relates to chemical compounds, and more particularly to chemical compounds having novel or enhanced odour properties, and to compositions including such compounds.

It has been found that certain dioxa-tricyclo-undecane compounds have desirable olfactory properties and can therefore be used in applications where such properties are desirable. The invention therefore provides a compound of the formula I

##STR00002## in which the moieties R.sup.1-R.sup.13 are independently selected from the following moieties: R.sup.1, R.sup.5, R.sup.6, R.sup.8, R.sup.11--H, methyl, ethyl, propyl, isopropyl; R.sup.3--H, methyl, ethyl, propyl, isopropyl, vinyl;R.sup.4--H, methyl, ethyl; R.sup.2, R.sup.7, R.sup.9--H, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl; R.sup.10--H, methyl, ethyl, propyl, isopropyl, t-butyl; R.sup.12, R.sup.13--H, C.sub.1-6 linear or branched alkyl; or R.sup.4 andR.sup.11 together with the carbon atoms to which they are attached form a 5- or a 6-membered cycloalkyl ring; or R.sup.6 and R.sup.7 together with the carbon atoms to which they are attached form a cycloalkyl ring having 3, 4, 5 or 6 members.

The definition hereinabove given encompasses all stereochemical forms of the compound. The compound hereinabove described may be a mixture of isomers, or, if desired, it may be resolved by known methods into individual isomers. However, as suchresolution inevitably adds to the cost of the process and therefore of the final materials, it is preferred to use the compound as a mixture.

A preferred compound is 8-isopropyl-2,4,4,10,10-pentamethyl-3,5-dioxa-tricyclo[6.2.1.0.sup.2,6]un- decane.

The compounds of the invention may be prepared by known methods, starting from the known compounds II

##STR00003## in which the moieties R.sup.1-R.sup.10 have the significances hereinabove defined.

The compounds of the invention have strong ambery woody and substantive odours and are useful in the preparation of fragrances and fragrance compositions. The invention therefore provides the use as a fragrance of a compound as hereinabovedefined.

The invention further provides the use in a fragrance composition of a compound as hereinabove defined.

The compounds may be used in a broad range of fragrance applications, such as fine and functional fragrances, including perfumes, cosmetics, body care products and household products, for example, laundry, dishwashing and dishwasher products,polishes and cleaners, and so on. The invention therefore also provides a fragrance application comprising at least one compound as hereinabove defined.

The invention is further described with reference to the following non-limiting examples.